When Chuck is at the airport talking to Kelly's husband, the scab above his eyebrow is big. By the time he's at her house, later that night, the scab has miraculously healed and is quite a bit smaller in size.
actually chuck doesn't go to Kelly's house that same night. between the two scenes it shows him in a hotel or apartment bedroom, sleeping on the floor and flicking a light on and off like he did on his first night on the island. so he might have waited a little while before going to see kelly.